Home      Discussion      Topics      Dictionary      Almanac
Signup       Login




(1)   (law) an explanation of the fundamental reasons (especially an explanation of the working of some device in terms of laws of nature)
"The rationale for capital punishment"
"The principles of internal-combustion engines"
(2)   A basic truth or law or assumption
"The principles of democracy"
(3)   A rule or law concerning a natural phenomenon or the function of a complex system
"The principle of the conservation of mass"
"The principle of jet propulsion"
"The right-hand rule for inductive fields"
(4)   A basic generalization that is accepted as true and that can be used as a basis for reasoning or conduct
"Their principles of composition characterized all their works"
(5)   A rule or standard especially of good behavior
"A man of principle"
"He will not violate his principles"
(6)   Rule of personal conduct


< < < ; see prince.


  1. A fundamental assumption.
    We need some sort of principles to reason from.
  2. A rule used to choose among solutions to a problem.
    The principle of least privilege holds that a process should only receive the permissions it needs.
  3. Moral rule or aspect.
    I don't doubt your principles; you are clearly a person of principle.
    It's the principle of the thing; I won't do business with someone I can't trust.
  4. A rule or law of nature, or the basic idea on how the laws of nature are applied.
    Bernoulli's principle
    The Pauli Exclusion Principle prevents two fermions from occupying the same state.
    The principle of the internal combustion engine
  5. A fundamental essence, particularly one producing a given quality.
    Many believe that life is the result of some vital principle.
    Cathartine is the bitter, purgative principle of senna. — Gregory.
  6. A beginning.
    Doubting sad end of principle unsound. — Spenser.

Usage notes

Principle (moral rule) is often confused with principal (most important.) Consult both definitions if in doubt.

The confused may care to remember that 'The principal alphabetic principle places A before E' as a reminder of the relative spelling.